Non-Class 125 VDC Control Power (NK)

Question 1

How many hours of battery power will NK provide on a loss of station AC power?

Answer 1

2 hours at full loading

Question 2

what is the design basis for NK?

Answer 2

Provide sufficient power for the protection and control of transformers, switchgear, and the digital
fault recorder.

Question 3

NK provides normal power source to plant computer (NQ) through what

Answer 3

inverter

Question 4

What are the M45 loads?

Answer 4

plant computer
NKN-D41, D42, D43
Main Generator primary and backup tripping circuits

Question 5

What is powered from NKN-D41?

Answer 5

Switchgear control power for NAN-S01/ S03, Main Generator Auxiliaries, Turbine Building HVAC

Question 6

What is powered from NKN-D42?

Answer 6

Switchgear control power for NAN-S02/ S04
Radwaste annunciators
Motor Operated Disconnects
Plant annunciators

Question 7

What is powered from NKN-D43?

Answer 7

Oscillograph
turbine protection
transformer annunciators
plant annunciators

Question 8

Normal control power for NAN-S05/S06?

Answer 8

M45 -> U45
M46 -> U46

Question 9

What are the NKN-M46 loads?

Answer 9

NKN-D44
NKN-D45
emergency pumps for:
Main Turbine
main generator
MFPT oil pump motors
containment personnel airlocks

Question 10

Where are the NK battery breakers normally operated from?

Answer 10

control room
can be done locally

Question 11

What relays/alarms exist for NK busses?

Answer 11

bus undervoltage
soft/hard ground

Question 12

How many fans are in the NK battery room and why are they important?

Answer 12

2 100% capacity exhaust fans in battery room

Prevent buildup of potentially explosive hydrogen levels

Question 13

What is the purpose of NKN-D19?

Answer 13

cooling tower fan load center control power

Question 14

How do you read the amp indications in the CR for NK batteries?

Answer 14

Amps to left (Battery charging)
Amps to right (Battery discharging)

Question 15

Are NK battery chargers make before break or the opposite?

Answer 15

normally make before break but can do either one

Question 16

What is provided to ensure the 120VAC UPS D-Panel, NQN-D01 remains energized on a loss of NKN-M45?

Answer 16

static transfer switch connected to a voltage regulator getting power directly from an MCC (M08)

Question 17

What is powered by NKN-D44?

Answer 17

RCP breaker controlW

Question 18

What is powered from NKN-D45?

Answer 18

SSO Cabinet (SSR room)

Question 19

What could bring in this alarm?

Answer 19

NKN-M45 Bus under voltage, ground, or breaker trip

Battery Charger E/EI overvoltage, undervoltage,
reverse current, AC supply undervoltage or charger
failure

Question 20

What could bring in this alarm?

Answer 20

NKN-M46 Bus under voltage, ground, or breaker trip

Battery Charger F/EF overvoltage, undervoltage,
reverses current, AC supply under voltage or charger
failure

Question 21

What could bring in this alarm?

Answer 21

NKN-D41/42/43 Bus under voltage, ground, or
breaker overload trip

Question 22

What could bring in this alarm?

Answer 22

NKN-D19 Bus under voltage, ground, or breaker trip

Battery Charger G overvoltage, under voltage,
reverse current, AC supply under voltage or charger
failure